The rapid expansion of the world's population coupled with the accelerated technological development of large sectors of the world has produced a dramatic increase in the demand for energy in all forms including fuels and electricity for heating, lighting, transportation and manufacturing processes. The construction of hydroelectric facilities and the development of fossil fuel resources has continued at a rapid rate, but it becomes increasingly evident for a number of reasons that these efforts are inadequate to keep pace with the demands of the growing population.
Until recently, the development of solar energy collectors has been associated for the most part with programs involving military and space applications while only limited attention has been given to broad consumer use. As a result, there is a great potential for improvements in existing collection devices that will result in reduced manufacturing costs and improved thermal efficiencies.
One such device knwon as a flat plate collector is made of metal and glass with one or more layers of glass laid over a blackened metal plate. Air spaces are provided between the layers of glass and air or water passes through tubes under the metal plate to remove the collected thermal energy. The layers of glass in cooperation with the blackened metal plate act as a heat trap, letting in the sun's rays but keeping most of the heat from escaping again.
Parabolic reflectors have also been utilized to concentrate the rays of the sun on a pipe that is positioned at the focal point of the reflector. The collected energy in the form of heat is transferred to air or liquid carried by the pipe.
For the effective and efficient operation of either of the above described collectors, it is necessary or at least desirable that the collector be trained at all times in the direction of the sun. Variations of equipment intended to meet such purposes are described in U.S. Pat. Nos. 1,162,505; 2,803,591; 3,118,437 and 4,000,734. Most systems of this type incorporate thereinto elaborate systems of gears and racks or other means to shift or otherwise change the positions of the exchange or collector unit so that its position relative to the source of heat remains approximately constant.
U.S. Pat. Nos. 3,421,004 and 3,996,460 disclose solar tracking devices employing photo sensors located within light vanes and a shadow box respectively. U.S. Pat. No. 3,857,638 discloses a protective tube to guide a light beam from an emitting source to a detector.
While such prior art inventions do suggest workable approaches for the realization of the important objectives involved, the particular implementations described in these patents have in general fallen short of what is required in a low-cost and practical system.
More specifically, what is needed to render solar energy collection economically feasible for use by the homeowner or small businessman is an extremely simple mechanically and electrically mechanism for the support and directional control of the collector unit.